Dr Hamid has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.

Direct-to-consumer (DTC) genetic tests, sold directly to the public without input from a health care provider, typically scan the DNA of an individual to determine the presence or absence of single nucleotide polymorphisms (SNP). DTC companies claim that testing will allow consumers to make more informed health care decisions and better lifestyle choices. Consumers have shown considerable interest in knowing genetic risk information and a willingness to pay for it, even if the results do not have immediate clinical value.

The health value of these services remains questionable. Most of the variants tested have relatively low penetrance, carry minuscule risk, and may not be causative. Association-based approaches provide correlation and not causation for these SNPs and are thus of limited useful predictive value in this context. For example, stating that a variant increases your risk for a disease by 60% sounds ominous; however, if the number is derived from an increase in absolute risk from 0.1% to 0.16%, the statement is essentially meaningless. Furthermore, associations between disease and SNPs have not been consistent among studies.

These tests, however, do have the potential to cause anxiety if a result indicates increased disease risk, or false reassurance if a result indicates decreased disease risk. They also raise consumer expectations that the health care provider will be able to explain the test results and order a test, even if it is not indicated. One study found that of those who expressed an interest in being tested, 78% said that they would ask their physicians for help interpreting the results, and 61% thought that physicians have a professional obligation to provide such help. However, another study of US physicians found that only 10% felt prepared to handle pharmacogenetic testing. Even if they felt comfortable in discussing the test results, the time constraint imposed by a typical 15–20 minute clinical encounter is not at all conducive to a discussion of relative risk, recessive versus dominant inheritance, or penetrance of 400–500 variants contained in a typical report. While some companies provide genetic counseling services, the majority effectively externalize the costs of counseling and education, in most cases leaving consumers to fend for themselves.

Regardless of the issues outlined above, DTC continues to grow and remain popular with consumers. With next generation sequencing technology becoming cheaper, many of the problems outlined above are likely to worsen. Regulatory agencies and professional physician organizations realize the complex nature of DTC and have started providing some guidance.4,5  These efforts need to continue.

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